Abstract

Potassium is very important nutrient to increase the production of good quality onions. However, so far there were no experiments conducted to rationalize the doses of potassium in Nubra valley of Ladakh. Field experiments were conducted with five, treatments of potassium (0, 20, 40, 60 and 80 kg K2O/ha) along with basal application of 6 t FYM, 4 t vermicompost and 2 t poultry manure per hectare in four replications under randomized block design on onion var. Brown Spanish for two consecutive years (2010 and 2011) at Defence Institute of High Altitude Research, Field Station, Partapur, Ladakh, J & K. Results revealed that the plant growth attributes like number, length and width of leaf, length, diameter and weight of bulb per plant increased significantly with the increasing application of potassium doses over control in each year. The pooled data of both the years showed maximum bulb yield 31150 kg/ha obtained at application of 80 kg K2O/ha followed by 30865 and 30170 kg/ha due to 60 and 40 kg K2O/ha, respectively, was significantly higher over other treatments. The sharp increase in marginal yield of bulbs was seen up to 40 kg K2O/ha, and after that it decreased even after increasing the doses of potassium. Pooled data indicated the increase in bulb yield per cent as 17.65, 12.78, 2.30 and 0.92, respectively, by successive doses of 20, 40, 60 and 80 kg K2O/ha. The maximum BCR 22.02 was obtained at 40 kg K2O/ha. It was, therefore, inferred that application of 40 kg K2O/ha along with 6 t FYM, 4 t vermicompost and 2 t poultry manure/ha was more rational for cultivation of onion compared to further increase of potassium doses in Nubra valley of Ladakh, Trans-Himalayas in J & K, India.